The present invention relates to an attachment member with a tubular shank the trailing, in the setting direction, end of which is provided with load application means. The invention also relates to a method of anchoring such an attachment member.
For effecting attachments to different solid constructional components, different methods are used. The -most common are sequential method and a method of direct mounting technology. The sequential method is suitable for all types of constructional components. Dependent on the type of a component and a desired degree of attachment, different attachment members are used. With a sequential method, a receiving bore is formed in a constructional component with a drilling device. The drilling device consists of a metal rotary or wood drill driven by a hand-held tool having a power rotary drive and, if necessary, impact application means. After a receiving bore is formed, an attachment member, usually a dowel, is inserted into the bore and is anchored in the bore, in most cases, by being expanded by screwing-in a screw or driving-in a mandrel. As mechanical attachment members, plastic or metal mandrels having a head can be used, which are driven in a prepared bore with a hammer. The retaining mechanism is primarily based on frictional engagement and, for perforated brick structures, sometimes on a form-locking connection.
With a direct mounting technology, special attachment members are directly driven into the component with powder explosion driven setting tools. With this attachment method, the step of separately forming the receiving bore is eliminated. The direct mounting technology is a rapid method and results in attachment with a high retention force. Generally, the known direct mounting technology is suitable for more or less ductile constructional components, e.g., such as steel, lime base, concrete, if necessary, wood.
Less strong or brittle constructional component, e.g., such as brick masonry, are very much affected by the powder explosion driven setting tools, which are used with the conventional direct mounting technology, and are often so damaged that no acceptable attachment takes place. Therefore, for anchoring in these constructional components, essentially only the sequential attachment method is used. It does not affect the constructional component and results in an acceptable attachment with desired retention values. Generally, a significantly larger expenditure of time for each attachment should be taken into consideration. In addition, separate devices for forming the receiving bores and for anchoring of attachment members or members are necessary. E.g., a drill tool with drilling means is necessary for drilling a bore, and a screwing tool for screwing a connection screw into a dowel, with the dowel being anchored by being expanded.
For attachment of insulation panels or for laying down cables or pipes in a constructional component, the attachment member is provided with specially formed load application means. German publication No. 4,432,780 of the assignee herein discloses load application means which is used, for example, for laying down cables or insulation pipes during electrical works. It has a base and an arched shackle projecting therefrom. In the base, a bore is formed through which an attachment member is driven into the constructional component. European Publication 0 492 230 and corresponding U.S. Pat. No. 5,171,118 disclose an attachment arrangement for insulation panels, wall paneling and the like. The attachment arrangement includes an attachment member for anchoring in constructional component and load application means with a large-area head. From the head, a shank member projects which has an axial passageway with an abutment for the attachment member extending through the passageway. The passageway opens at the head and is closed, e.g., with reversible resilient lamellas. The mechanical attachment of insulation panel, e.g., when heat insulation connection systems are used, is used either along or in addition to gluing of the panels.
When the constructional component is formed by more or less brittle brick masonry, only the sequential attachment method is conventionally used for an attachment. Expansion dowels or plastic or metal mandrels are usually used as mechanical attachment members, which are provided with a large-area head, and are inserted and anchored in the preliminary prepared bore. When an insulation panel is being attached, it is rather difficult to find the receiving bore behind the insulation panel. This results in a loss of time, troubles, damaged dowels, which should be anchored, and so forth. Often, forming of a new receiving bore is required. Further drawback consists in that during a sequential mounting of the insulation panel, the quality of attachment during mounting cannot be controlled. Usually, the trailing end of the plastic or metal mandrel or its head is struck with a hammer until it becomes flush with the outer surface of the insulation panel. It becomes, as a result of hammer blows, plastically deformed. The head indeed becomes flush with the insulation panel and is slightly submerged in the material of the insulation panel. However, the operator is not sure whether the connection means secured the insulation panel to the constructional component with a required minimal retention force. The setting results can usually be determined only with pull-out devices.